An electrically powered can opener

ABSTRACT

An electrically powered can opener comprising cutter blade operable by manually operated actuator which is operatively connected with cam plate operable to close electric switch for motor for driving feeding gear which in turn rotates and feeds can to be opened so that the latter is urged into cutting engagement with cutter blade. A spring is provided between cutter blade and actuator to allow same to have limited downward lost motion relative to cutter blade so that manual force on actuator is not required to drive cutter blade into cover of can. The spring holds cutter blade in engagement with opened can so that cutter blade cooperates with feeding gear to pinch edge of opened can.

United States Patent Fukunaga et al.

[54] ELECTRICALLY POWERED CAN OPENER [72] Inventors: Masao Fukunaga,lchioka, Minatoku, Osaka; Kiyoyuki Amo, Amagasaki-shi, both of Japan[73] Assignee: Matsushita Electric Industrial Co. Ltd., Osaka, Japan[22] Filed: Nov, 5, 1970 [2l] Appl. No.: 87,053

[30] Foreign Application Priority Data Nov. 8, 1969 Japan ..44/89465Nov. 8, 1969 Japan ..44/89466 Nov. 8, 1969 Japan ..44/89467 Nov. 8, 1969Japan ..44/89468 Nov. 8, 1969 Japan ..44/89469 [52] U.S. Cl. ..30/4 R [5l] Int. Cl. B67b 7/38 [58] Field of Search ..30/4 A, 4 R, l0, ll

[451 Dec.V 179, 1972 Primary Examiner-Robert C. Riordon AssistantExaminer-Gary L. Smith Attorney-Stevens, Davis, Miller & Mosher [57]ABSTRACT An electrically powered can opener comprising cutter bladeoperable by manually operated actuator which is operatively connectedwith cam plate operable to close electric switch for motor for drivingfeeding gear which in tum rotates and feeds can to be opened so that thelatter is urged into cutting engagement with cutter blade. A spring isprovided between cutter blade and actuator to allow same to have limiteddownward lost motion relative to cutter blade so that manual force onactuator is not required to drive cutter blade into cover of cani. Thespring holds cutter blade in engagement with opened can so that cutterblade cooperates with feeding gear to pinch edge of opened can.

11 Claims, 25 Drawing Figures PTNTUECISIS?? 3.706.135

SHEET 1 UF 8 INVENTORY ATTORNEYS Byw/M M/w PATENTED nic 19 |972 SHEET 30F 8 PATENTED nic 19 |912 SHEET l# UF 8 PATENIEDUEC 19 |912 3. 706; 135

SHEEI 7 0F 8 INVENTOR ATTORNEY AN ELECTRICALLY POWERED CAN OPENERBACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention relates to an electrically poweredcan opener having a camplate for opening and closing the electrical circuit for an electricmotor, a feeding gear driven by the motor,l a cutter blade forcooperating with the feeding gear to hold the peripheral edge of a canto be opened and for cutting the cover thereof, and a push-button typeactuation rod for operating the cam plate and the cutter blade.

2. Description of a Prior Art U.S. Pat. No. 3,314,145 discloses aconventional electrically powered can opener of this kind. The canopener disclosed in this patent is designed to be automaticallydeenergized when a can opening operation is completed. Thev can opener,however, utilizes a manually operated lever to drive the cutter bladeinto the cover of a can to be opened and dismount or disengage theopened can from the can opener. Specifically, the can to be opened isrotated with its peripheral edge pinched between the feeding gear andthe cutter blade. The cutter blade is wedged into the cover of thevcansubstantially at the same time'as the start of the rotation of the can.Thus, it is difficult to easily drive the cutter blade into the cover ofa can unless the manually operated lever is actuated with a largemagnitude of manual force. In addition, when a can opening operation iscompleted, the cutter blade is stopped with the forward end thereofengaging the inner peripheral edge of the opening thus formed in thecover of the opened can. The dismounting of the opened can is performedby actuating the manually operated lever to move the feeding gearagainst the friction between the opened can and the cutter blade. Thus,a large magnitude of force is required to manually operate the lever indismounting an opened can from the can opener.

Moreover, the manually operated lever is pivotally mounted on asupporting shaft and, thus, must be operated through a widened rangevand in a complicated manner.

SUMMARY OF THE INVENTION It is a general object of the present inventionto provide an improved electrically powered can opener which is freefrom the difficulties above-discussed.

Specifically, the present invention contemplates an improvement in thecam plate and the arrangement for the operative connection between thecam plate, the cutter blade andthe actuation rod of an electricallypowered can opener of the kind above-specified so that the actuation rodcan be actuated with a reduced magnitude of force to operate the cutterblade at the beginning of cutting operation at which the cutter blade iswedged into the cover of a can to be opened and at the end of the canopening operation at which the cutter blade is lifted to allow the thusopened can to be dismounted. With the above improvement, it is alsointended to automatically stop the operation of the can opener when thecover of a can is completely cut.

According to the present invention, there is provided an electricallypowered can opener comprising an electric motor, a feeding gear mountedfor rotation about a fixed axis and operatively connected to said motorto rotate and feed a can to be opened, a cutter blade mounted forpivotal movement about the axis of a supporting shaft therefor, saidblade being voperable to cooperate with said feeding gear to pinch andhold such can so that said blade cuts the cover thereof, a cam platemounted for pivotal movement about the axis of a supporting shafttherefor, said cam plate being pivotally successively movable to afirstposition in which the electrical circuit for the motor is closedwhen said cutter blade is positioned above said cover, to a secondposition in which said circuit is kept closed from the time said cutterblade is driven into said cover to the time said cutter blade completesits cutting to said first, second and fourth positions and for.

stopping the pivotal movement of said cam plate at said third position,meanl responsive to the pivotal movement of said cam plate for pivotallymoving said cutter blade, and common means for actuating both of saidcam plate moving means and said cutter blade moving means.

The common means is advantageously of a push-button type actuator. Thecan opener is designed such that the electrical circuit for the motor isclosed when the cutter blade is cooperating with the feeding gear topinch the peripheral edge of a can to be opened and is positioned abovethe cover of the can. The can to be opened is power-driven so that thecover of the can is urged into cutting engagement with the cutter blade.This makes it possible to depress the actuator with an extremely reducedmagnitude of pressure force. When a can opening operation is completed,moreover, the electrical circuit for the motor is opened to deenergizethe motor while the cutter blade is held in engagement with the innerperipheral edge of the opened can so that the latter is prevented fromfalling down off the cutter blade and the feeding gear.

A clearance or a lost motion is advantageously provided between theactuation means and the cutter blade to prevent the force of theactuation means from being transmitted to the cutter blade when theactuation means is depressed to cause the cam plate to be moved from thethird position to the fourth position so that the opened can which isheld between the cutter blade and the feeding gear may be dismountedfrom the can opener. This arrangement assures reduction in the y forcerequired to depress the actuation means when an opened can is dismountedfrom the can opener because the cutter blade is not lowered into theopened can.

A spring member is conveniently provided not only to resiliently holdthe power transmission means on the actuation rod in operativeconnection with the cutter blade but also to be deformable a distancecorresponding to the above-mentioned clearance or lost motion. Namely,as stated in the above, the said clearance is provided to prevent thedownward force from being transmitted from the actuation rod to thecutter blade when the cam plate is pivotally moved from the thirdposition to the fourth position so that an opened can may be dismountedfrom the can opener. If the spring were not provided, the cutter bladewould be first lowered into the opened can and then lifted away off theopened can a distance corresponding to the return movement of theactuation rod, with a resultant disadvantage that the opened can willfall down off the can opener. In fact, however, the spring memberadvantageously takes up, by its resilient deformation, the part of thedownward movement of the actuation rod which part correspondsto the saidclearance during the movement of the cam plate from the second to thethird positions so that the cutter blade is not lowered into the openedcan. The spring is also operative to retain the cutter blade inengagement with the peripheral edge of the can so r`that the blade cancooperate with the feeding gear to hold the can on the can opener whenthe actuation rod is returned to its initial position. In addition, thespring is operative to surely transmit the force from the actuation rodto the cutter blade at the beginning of a can opening operation so thatthe cutter blade is lowered a limited distance, i.e., to the uppersurface of the cover of the can to be opened. Thus, the force requiredto depress the actuation rod is greatly minimized.

The above and other objects and features of the present invention willbe made clear by the following description of a preferred embodiment ofthe invention with reference to the accompanying drawings.

DESCRIPTION OF DRAWINGS FIG. l is a front elevational view of anembodiment of the electrically powered can opener according to thepresent invention with some components within the housing being shown bybroken lines;

FIG. 2 is a top plan view of the can opener in FIG. l;

FIG. 3 is a vertical sectional view of the can opener;

FIG. 4 is a fragmentary sectional side view taken substantially alongline IV-IV in FIG. l and illustrates the arrangement between a cutterblade, a feeding gear and driving connections thereto, respectively;

FIGS. 5A, 5B, and 5C through 8A, 8B and 8C illustrate the cutter bladeand a related switching mechanism at each stage of successive operationof the can opener, in which, y

FIGS. 5A, 6A, 7A and 8A illustrate, in fragmentary side elevations, thesuccessive operations of the switching mechanism,

FIGS. SB, 6B, 7B and 8B illustrate, in fragmentary side elevations, therelative positions of the cutter blade with respect to a can beingopened at respective stages of operation,

FIGS. 5C, 6C, 7C and 8C illustrate, in fragmentary sectional sideelevations, the relative positions of the cutter blade with respect tothe can at respective stages shown in FIGS. 5B, 6B, 7B and 8B;

FIG. 9 illustrates in side elevation the switching mechanism which isoperating to unlock the cam plate shown in FIG. 8A;

FIG. 10 is a fragmentary sectional view taken along line X in FIG. 8Aand illustrating the relationship between an actuation rod and atransmission shaft;

FIG. l1 is a fragmentary sectional view of the cam plate taken alongline XI XI in FIG. 8A;

FIG. 12 is a fragmentary sectional view of a part of the switchingmechanism taken along line XII XII in FIG. 8A;

Referring to FIGS. l to 4 of thedrawings, the electrically powered canopener of the present invention has a casing comprising a front casingpart l and a rear casing part 2 united together by means of fasteningscrews 3. A framemember 4 is Vsecured to the inner surface of the frontcasing part l by means of screws 6 threadably engaging with bosses 5 onthe inner surface of the casing partl. An electric motor comprising arotor 7 and a stator 8 is mounted on the frame 4 by means of screws l 10extending through the stator 8. intobosses 9v on the Y frame member 4.The motor has a rotor shaft l1 extending through the rotor 7 forrotation therewith and having ,one end rotatably received Aby a bearingl2 mounted on the frame member 4 while the other end of the rotor shaftl1 is rotatably supported by a bearing 14 housed in a bearing fitting 13secured to the stator 8'by means of screws l0.

The rotor shaft ll is formed with a first helical gear l5 on the portionthereof adjacent said one end. A second helical gear 16 of a largerdiameter is rotatably mounted on a shaft 18 rigidly mounted on a boss 17on the frame member 4, said helical gears 15 and 16 being in meshingengagement with each other. A first spur gear 19 is mounted on the shaft18 for rotation with the second helical gear 16. A second spur gear 20of a larger diameter is rigidly secured to one end portion of a shaft 22which rotatably extends through a bearing portion 2l of the frame member4, said second spur gear 20 being in meshing engagement with the firstspur gear 19.

The rotatable shaft 22 has its other end portion projecting outwardly ofthe front casing part l. A feeding gear 23 is rigidly mounted on theother or outer end of the shaft 22. The feeding gear 23 is driven torotate in counter-clockwise direction by the motor. Namely, the torqueof themotor is transmitted through the first and second helical gears 15and 16 and the first and second spur gears 19 and 20 then to the feedinggear 23. A cutter blade 24 for opening a cover 26 of a can 25 is rigidlymounted on an outer end of a boss 29 by means of a screw 30. The boss 29movably extends through a guide slot 28 in the front casing part ll andthe frame member 4 and is rigidly connected at its inner end with an endportion of a generally triangular arm 31 which is pivotally mounted atthe other end portion on a shaft 27 fixed to the frame 4. The pivotalarm 3l is operatively related to a switching mechanism, which is to bedescribed later, so as to be pivotally moved about the shaft 27 forthereby causing the cutter blade 24 to move downwardly along the guideslot28 into a cover 26 of a can 25 to cut and open the cover along acircle adjacent a sealed peripheral edge 25a of the can. During thecutting or can opening operationof-the blade 24, the can 25 is held suchthat the sealed peripheral edge 25a of the can is supported by thefeeding gear 23 while the latter is operating to rotate the can incounter-clockwise direction. In order that the cutter blade 24 mayadvantageously perform the cutting operation in the above-stated manner,the cutter blade 24 is laterally offset a distance a from the outer endface of the feeding gear 23, as will be seen in FIG. 4.

A coil spring 32 is provided to extend around the bearing portion 21 sothat the spring biases the second spur gear inwardly or rightwardly asviewed in FIG. 3. The distance a between the cutter blade 24 and thefeeding gear 23 is adjusted at the time of assembly of the apparatus byinterposing a spacer ring 33 between the feeding gear 23 and the bearingportion 2l. For this purpose, the rotatable shaft 22 is dimensioned inlength such that a space is left between the second spur gear 20 and thebearing portion 21. The spring 32 is intended to always bias the shaft2l rightwards so that the feeding gear 23 is held axially spacedaccurately the distance a from the cutter blade 24.

At the intermediate portion of the pivotal arm 31 is rigidly mounted arod-like transmission shaft 34 for transmitting the motion of theswitching mechanism to the arm 31.

Referring now to FIGS. 5 through 13, a description will be made withrespect to the switching mechanism for the electric motor and withrespect to the successive can-opening operation of the cutter blade 24related to the switching operation of the switching mechanism. Thelatter includes a push-button 35 mounted on the top of an actuationmember 36 in such a manner that the button 35 projects u'pwardly fromthe top of the rear casing part 2. The actuation member 36 extendsslidably through openings 39 formed in the top and bottom walls of aswitch cover 38. A compression coil spring 40 is provided to extendaround the leg portion 41 of the actuator member 36 so that the. springalways biases the latter upwardly. The actuation member 36 is formedtherein with a hole 42 through which the transmission rod 34 of thepivotal arm 3l extends laterally so as to transmit the motion of theactuation member 34 to the pivotal arm 3l and to the cutter blade 24.The hole 42 is sized such that a gap or clearance b is provided betweenthe peripheral edge of the hole and the transmission rod 34 for thereasons which will be discussed later. A leaf spring 43 is rigidlymounted at one end on the actuation member 36. The spring 43 is inpressure contact at the other end portion with the upper surface of thetransmission rod 34 so that the latter is urged against the lower edgeof the hole 42 to thereby avoid the chatter which would otherwise becaused due to the above-mentioned clearance b.

A projection 44 extends from the actuation member 36 laterally through avertical slot 45 formed in the side wall of the switch cover 38. A camplate 46 is pivotally mounted at its lower end on a pin 47 which issecured to the switch cover 38. The cam plate 46 has a hooklike camprojection 48 at which the cam plate 46 is contacted and pressed by theprojection-44 when the latter is lowered by the actuation by theactuation member 36 so that the cam plate 46 is rotated in clockwisedirection. A tortion spring 49 is provided to extend around the pin 47.The spring 49 has its one end engaged with a punched-out projection 50on the switch cover 38 and the other en engaged with a projection 5l onthe cam plate 46 so that the latter is always urged in counter-clockwisedirection by the spring 49. Thus, it will be appreciated that the camplate 46 is rotated in clockwise direction when actuated by theactuation member 36 and is rotated in the reversed or counter-clockwisedirection by the spring 49 when-the force by the actuation member 36 isremoved. v

A pair of contact plates 52 and 53 having contact points 54a and 54b attheir one ends are secured by means of rivets 56 to an insulation plate55 interposed between the plates 52 and 53. The insulation plate 55 issecured to the switch cover 38 and a support plate 57 secured to thecover 38. A plate 58 of an electrically insulating material is pivotallymounted on the switch c over 38 and the support plate S7 by means ofprojections 59 engaged into apertures 60 formed in the cover 38 and theplate 57. The arrangement is such that when the cam plate 46 is actuatedto rotate in clockwise direction, the cam plate is brought into pressurecontact with the plate 58 so that the latter is also rotated in the samedirection to urge the contact plate 52 towards the other contact plate53 to thereby cause the contact point 54a to bebrought into electricalcontact with the contact point 54b, as shown in FIG. 6A and 7A, wherebyelectrical current is fed through lines 61 and 62 to the motor.

The cam portion 48 of the cam plate 46 has its upper surface 63 inclinedforwardly and downwardly to provide a guide surface for the projection44 on the guide surface 63 is set such that, when the projection 44 hasbeen lowered to the position shown in FIG. 6A along the vertical slot 45in the switch cover 38, the cam plate 46 has been rotated, by the camaction between the projection 44 and the inclined guide surface 63, to aposition in which the cam plate causes the points 54a and 54b to becontacted with each other for switching on the motor. By that time, thecutter blade 24 is moved to a position in which the blade 24 and thefeeding gear 23 cooperate together to pinch the peripheral edge 25a of acan 25 therebetween, as best shown in FIG. 6C.

Under the inclined guide or cam surface 63, the cam plate 46 is formedwith a cut-out 64 of a generally hook-like shape. The cut-out 64 isprovided for the fol lowing reasons: When the actuation member 36 isfurther moved from the position shown in FIG. 6A to the position shownin FIG. 7A, the projection 44 is moved downwardly beyond the lower endextremity of the cam surface 63 into contact with a guide surface 65adjacent the cut-out 64. At this position of the projection 44, thecutter blade 24 is operating to cut a cover 26 of a can 25 as best shownin FIG. 7C. When the cutter blade 24 is in its FIG. 7C position, theprojection 44 is held in contact with the guide surface 65, as shown inFIG. 7A, by the frctional force produced between the cutter blade 24 andthe cut edges of the can cover 26 and, when the cutting operation of theblade 24 is completed, the frctional force is no more sufficient to holdthe cutter blade 24 in engagement with the cut edges of the cover 26 sothat the blade 24 is returned or moved to a position shown in FIG. 8A,with a result that the projection 44 is moved upwardly into lockingengagement with the hook-like cut-out 64.

The upward movement of the projection 44 allows the cam plate 46 to berotated in counter-clockwise direction to such an extent that theelectrical connec` if f tion between the contact points 54a and 54b isbroken.

Adjacent the locking cut-out 64, the cam plate 46 has an inclinedprojection 66 formed by punching-out the material of the cam plate. Whenthe projection 44 further moved downwardly by the actuation of thepush-button 35 and the actuation member 36 to a position in which theforward end of the projection 44 arrives at an undersurface 66a oftheinclined projection 66,*the cam. plate 46 is rotated incounter-clockwise direction from the position shown in FIG. 8A to theposition shown inv FIG. 9. In this position, if the downward pressure onthe push-button 35 and hence the actuation member 36 is removed, thelatter is allowed tobe moved upwardly by the action of the spring 40.Atthis time, the upward movement of the actuation member 36causes theprojection 44 to urge and move the cam plate 46v in an axial directionof the pin 47 against the spring 49 for the cam plate 46 by the camaction between the forward end of the projection 44 and the undersurface66a of the inclined projection 66 on the cam plate 46.v For thispurpose, the cam plate 46 is mounted on the pin 47 for either slidingmovement therealong or oscillatory or rocking movement in axialdirection of the pin 47. Alternatively, the projection 44 may be mademovable in its axial direction with respect to the inclined projection66 of the cam plate 46. Thus, the projection 44 is released and unlockedfrom the locking cut-out 64 so that the projection 44 is returnedtogether with the actuation member 36 to the FIG. 5A position.

Referring now to FIGS. 14A through 15B, a can bearing 67 is mounted onand projects from the front casing part l beneaththe feeding gear 23 forbearing against a barrel portion 68 of a can 25 being opened. Thebearing 67 has a generally rectangular configuration which issubstantially symmetrical in top plan view with respect to a verticalplane passing through an axis 69 of the feeding gear 23. Moreparticularly, the bearing has a rounded convex left end corner orprojection 67a projection outwardly from a generic surface of thebearing 67, and a right end comer or projection 67b substantiallysimilar in shape to the corner 67a but projecting outwardly in the samedirection a distance somewhat less than that of the projection 67a. Arecess is formed between the left and right projections 67a and 67b forreceiving a part of the peripheral surface of the can barrel 68, as willbe seen in FIGS. 14A to 15B. The left projection 67a is adapted to bearagainst the barrel 68 of a can 25 when its cover 26 is being cut whilethe other or right projection 67b is designed to bear against the barrelwhen can opening operation is almost completed.

While reference to FIGS. l to 3, a pair of spaced can holding orpressing rods 70a and 70b are rigidly mounted on and extend laterallyoutwardly from the front casing part l on opposite sides of the slot 28between the axes of the feeding gear 23 and the screw 30. The right handrod 70a is designed to bear against the peripheral edge of a can beingopened to hold down the can and prevent same from being lifted up duringf opening operation therefor while the left hand rod 70b isadapted tocooperate with the right hand rod 70a to prevent the can from beingcaused to have reciprocated oscillatory movement which is apt to'becaused for the following reasons: The can is held in engagement with therod 70a during cutting operation in such a manner that the top cover ofthe can is somewhat rightwardly upwardly inclined with respect to thehorizontal. When the cover is completely cut to open the can, theapplication of the force from the cutter blade to the can is suddenlydiscontinued. Thus, the opened can is oscillated by gravity in avertical plane in clockwise-direction into contact with the other rod70b and then is oscillated in opposite direction. The oscillation willbe repeated for a while until the can is stopped upright.

Now the operation of the apparatus by the cooperation of the cam plate46, the electrical contacts 54a and 54b and the cutter blade on thepivotal arm 3l which are actuated by the push-button 35 through theactuation member 36 will be described with reference to FIGS. A through9. First,lan operatorpositions a can to be opened in such a manner thatthe edge 25a of the can is engaged with the upper portion of theperiphery of the feeding gear 23 and the barrel 68 of the can is heldagainst the can bearing 67.'In the position shown in FIG. 5A, sincethep'ush-button 35 is not depressed,rthe actuation member'36 is notvlowered.

- Thus, neither the cam plate 46 nor the pivotal arm 31 is rotated and,thus, the electrical contacts 54a and 54b are maintained separated apartfrom one another. The cutter blade 24 is positioned above a cover 26 ofthe can 25 as shown in FIGS. 5B and 5C.

Then, the push-button 35 is depressed to some extent as shown in FIG.6A. The actuation member 36 is thus lowered to cause the projection 44thereon to be brought into pressure contact with the inclined camsurface 63 of the cam portion 48 of the cam plate 46 so that the latteris caused to rotate about the pin 47 vin clockwise direction. The plate58 is therefore rotated in the same direction to urge the contact plate52 lso that its contact point 54a is brought into contact with the othercontact point 54b whereby electrical current is fed to the motor. Therotor 7 of the motor is thus rotated and the torque thereof istransmitted through the first and second helical gears l5 and 16, thefirst and second spur gears 19 and 20 and the rotatable shaft 22 to thefeeding gear 23. At the same time, on the other hand, since thetransmission shaft 34 on the pivotal arm 3l is pinched between theretaining spring 43 and the bottom edge of the hole 42 in the actuationmember 36, the shaft 34 is downwardly moved together with the member 36.This downward movement rotates the pivotal arm 3l about the fixed pin 27to cause the cutter blade 24 to arrive at the position, shown in FIGS.6B and 6C, in which the forward end of the cutter blade 24 leaves adistance c (FIG. 6B) to the top surface of the cover 26 of the can 25and in which the edge 25a of the can is pinched between the feeding gear23 and the cutter blade 24. The can 25 in this position, therefore, isnot allowed to fall down off the can opener even if the manuallygripping force on the can is released or removed from the can and thelatter is rotated about its axis in counter-clockwise direction by thefeeding gear 23 rotating in the same direction.

lf the push-button 35 is further depressed to the position shown in FIG.7A, the actuation member 36 is similarly further moved downwardly tocausethe projection 44 thereon to slide over the inclined cam surface 63and arrive at the guide surface 65 for the locking cut-out 64 in the camplate 46 so that the cam plate 46 is further rotated in clockwisedirection to hold the contact points 54a and 54b in closed position asshown in FIG. 7A.

At the same time, the pivotal arm 31 is also further rotated inclockwise direction as shown in FIG. 7B so that the cutter blade 24 isdriven into the cover 26 of the can 25 and automatically severs thematerial of the cover 26 by virtue of the counter-clockwise rotation ofthe can caused by the feeding gear 23. During the can opening operationof the cutter blade 24, it is not required to manually hold down thepush-button 35 because the cutter blade 24 is maintained projecting intoand engaging with the cut edges in the cover 26 by the frictiontherebetween.. In other words, not only is it unnecessary to hold downthe push-button 35 but also it is not required to manually hold the canduring opening operation therefor. The apparatus is operable toautomatically perform a can opening operation.

It will be appreciated that, since it is the rotation of actuationpush-button 35. This means that a push-button type electric switchingmechanism may be employed as the switch for the electrically powered canopener of the present invention.

When the cover 26 of the can has been severed completely, the cutterblade 24 and the switching mechanism will have positions shown in FIGS.8A and 8C, respectively. Specifically, since no cutting resistance isexerted to the cutter blade 24 any longer, the actuation member 36 islifted by the action of the compression spring 40. The projection 44 onthe actuation member 36 is guided by the locking cut-out 64 to move intocontact with the side end face of the inclined projection 66 at thebottom of the cut-out 64 and is locked thereby. This movement of theprojection 44 changes the points of contact thereof with the cam plate46 so that the latter is rotated in counter-clockwise direction by thespring 49, with a result that the pressure force by the cam plate 46 isremoved from the plate 58 to allow the contact plate 52 to return to itsoriginal position for thereby separating the contacts 54a and 54b apartfrom each other.

The transmission rod 34 pinched between the retaining spring 43 and theperipheral edge of the hole 42 in the actuation member 36 is also liftedin a similar manner to the rod 36 so that the free end of the pivotalarm 31 is moved upwardly to lift the cutter blade 24 to the position inwhich the blade still extends into the cover 26a a distance d, as shownin FIG. 8B. The can 25, therefore, is not allowed to freely fall downbecause the edge 25a is still pinched by the feeding gear 23 and thecutter blade 24.

Then, the push-button 35 is again depressed downwardly to move theprojection 44 of the actuation member 36 within the locking cut-out 64along and past the side end face of the inclined projection 66 to aposition below the bottom end of the projection 66. In this position ofthe projection 44, the forward end ex tremity thereof is laterallyspaced from the bottom end face of the inclined projection 66 andpositioned beneath the undersurface thereof. Thus, if the pressure isremoved from the push-button 35, the compression spring 40 lifts theactuation member 36 to cause the projection 44 to slide upwardly alongthe undersurface 66a of the inclined projection 66 to the position shownin FIG. 5A while the cam plate is not rotated in any direction so thatthe contacts 54a and 54b are held opened.

The cutter blade 24 is also returned to the position shown in FIGS. 5Band 5C. The opened can is therefore disengaged both from the feedinggear 23 and the cutter blade 24 and, thus, may be dismounted from theapparatus by a single hand. j

In the event that the cutter blade 24 should have been clogged by theedge of the opened can sandwiched between the cutter blade 24 and thefeeding gear 23, the switching mechanism can be positively unlocked. Thedownward movement of the actuation member 36 is not required to furtherdownwardly move the cutter blade 24 from the position shown in FIGS. 8Band 8C. This is because of the reasons that the clearance b is providedbetween the transmission shaft 34 and the peripheral edge of the hole 42in the actuation member 36, said distance b being necessary for theprojection 44 to be moved a distance along and past the side edge of theinclined projection 66, and that the retaining spring 43 is designed tohave a sufficient resiliency for the spring to be resiliently bent ordeformed upwardly, as shown in FIG. 9, to take up the part of thedownward movement of the actuation member 36 which corresponds to thedistance b. It will be therefore appreciated that an extremely smallermagnitude of pressure is sufficient to depress the pushbutton 35 whenthe depression is to unlock the projection 44 from the cut-out 64 and toreturn the related components to their initial positions.

Unless the retaining spring 43 is provided, there will be a possibilitythat, since the clearance b is provided between the transmission rod 34and the peripheral edge of the hole 42, the cutter 24, when it lhascompleted its cutting operation (FIGS 7B and 7C), is upwardly moved adistance which includes the distance b so that the opened can isdisengaged from between the cutter blade 24 and the feeding gear 23 andfalls down therefrom. In fact, however, the transmission shaft 34 of thepivotal arm 3l is pinched between the retaining spring 43 and the bottomedge of the hole 42 so that the cutter blade 24 is maintained in theposition shown in FIGS. 8B and 8C thus to prevent the can from otherwisebeing disengaged from the apparatus upon completion of the openingoperation thereof, with a resultant advantage that the operator is notrequired to stand aside the apparatus for watching the can openingoperation.

As having been described in the above, the switching mechanism of thecan opener of the present invention is arranged such that the apparatusis switched on with the cutter blade positioned above a cover 26 of acan 25 leaving a distance c therebetween, as shown in FIG.

6B, and is switched off with the cutter blade projectingA into the cover26 a distance d, as shown in FIG. 8B so that a larger distancecorresponding to the distance c plus the distance d is provided betweenthe positions at which the apparatus is switched on and off,respectively. It will be understood that the apparatus is impracticalunless it is switched off with the cutter blade 24 positioned below aposition of the blade at which the apparatus is switched on.

Referring now to FIGS. 14, l and l, a description will be made withrespect to the can bearing 67 and to the can bearing rods'70a and 70b.When the cover 26 of can 25 is being cut as illustrated in FIGS. 7B and7C, the cutter blade 24 is positioned in a vertical plane 69 whichpasses through the axis of the feeding gear 23. In this position of theblade, the central axis of the can 25 is included in the vertical planeandthe barrel 68 of the can 25 bears against the left end projection 67aof the bearing 67, as illustrated in FIG. 14A. When the can is opened,the cutter blade 24 is moved a distance e in counter-clockwise directionto a position illustrated in FIG. 8B. By this movement, the barrel 68 ofthe can 25 is allowed to have a slight rolling movement -by gravityalong the arcuate surface of -the recess between the projections 67a and67b into abutment contact with the latter. In this position, the centralaxis of the cutter blade 24 is coincident with the axis of the can 25,as illustrated in FIG. 15A.'Thus, the relationship between the cutterblade 24 and the can 25 is kept unchanged with the exception that thegap between the cutter blade 24 and the peripheral edge 25a of the can25 iswidened. This ensures easier and simultaneous returning of thecutter blade 24 and the switching mechanism to their initial positions.

With respect to the can bearing rods 70a and 70b, since the edge 25a ofthe can 25 receives an upward force which tends to pivot the can 25 incounterclockwise direction about the right hand rod 70a due to therotation of the feeding gear 23 so that the right side portion of theedge 25a of the can is urged against the rod 70a. When the can isopened, on the other hand, the upward force is no more exerted on theright hand portion of the can 25 and, for this reason, the can is apt tobe oscillated in the opposite direction or clockwise direction by theforce of gravity of the can and is driven against the other or lefthandrod 70b. The can is again oscillated in counter-clockwise directionbyreaction force by the rod 70b into contact with the right hand rod70a. The oscillation is discontinued after a few reciprocated movementsof oscillation.

As described hereinabove, the can opener of the present inventionemploys a push-button type electric switch which is operativelyconnected to the cutter blade. This ensures a simplified operation ofthe apparatus. The push-button type switch utilizes a cam to open andclose the electrical contact points. It is, therefore, possible to causethe cutter blade to have stepped motion in downward and/or upwardmovement thereof. This satisfies the requirements for the operation ofthe apparatus in that the cutter blade is caused to have their differentpositions, one being the position in which the cutter blade operates toopen the cover of a can, another being the position at which the bladeis automatically stopped after completion of the cutting operation andthe other being the position to which the blade is returned, so that thecutter blade cooperates with the feeding gear to firmly griptherebetween the peripheral edge of an opened can to'prevent the samefrom falling down off the can opener when the cutter blade isautomatically stopped upon completion of can opening operation. Inaddition, the cutter blade is returned to its original position by theoperation of the switch so that the opened can may be dismounted fromthe apparatus. This provides an advantage that the can opener of theinvention is operable automatically and is entirely free from'atroublesome manual service that an operator is required to stand asidethe apparatus during can opening operation so as`to receive an openedcan in his hands. l

The push-button type switch which is operatively connected to the cutterblade has its cam which is shaped such that the opener is switchedon andoff at different positions of the cutter blade with respect to the coverof a can which is placed in position on the apparatus. Namely, the motorofk the can fopener is switched on when the forward end of the cutterblade is positioned below the top of the peripheral edge of the can tocooperate with the feeding gear to grip the peripheral edge so that thecutter blade is driven into the cover of the can by the rotation of thecan caused by the feeding gear. Thus, a pressure force large enough todepress the push-button of the switch will be sufficient to cause thecutter blade to cut into the material of the cover of a can. Also, whencan opening operation is completed, the motor of the can opener isswitched off with the forward end of the cutter blade being positionedbelow the top of the peripheral edge of the opened can so that the bladecooperates with the feeding gear to grip the peripheral edge of the canto prevent the latter from falling down.

Moreover, the push-button switch is held in its on position during a canopening operation by the cutting blade and the material of the coverbeing cut. The switch is shifted to its off position upon completion ofthe cutting operation and is held in this position. In this position ofthe switch, the cutter blade is stopped at a position below the cover tocooperate with the feeding gear to pinch the peripheral edge of theopened can. The push-button switch is depressed so -as to be unlocked sothat the cutter blade is returned to its original position. The powertransmission means interposed between the cutter blade and the switch isprovided with a clearance within which the push-button switch is allowedto have a downward lost motion with respect to the transmission means.This clearance corresponds to the distance through which the push-buttonswitch is moved so as to be unlocked. The lost motion prevents theunlocking movement of the push-button switch from being subjected to africtional resistance which will otherwise be produced between thecutter blade and the inner peripheral edge of the opened can and, thus,makes it possible to actuate the push-button with an extremely reducedmagnitude of pressure force. For this reason, a push-button type switch,which is more conveniently useful as compared with other types ofswitches, may easily and advantageously be utilized in the can opener tomake the same more conveniently operable.

The clearance for the above-mentioned downward lost motion of thepush-button switch is advantageously taken up by the retaining springwhich is provided to hold down the transmission means. Namely, if theretaining spring were not provided, the cutter blade, upon completion ofits cutting operation, will be moved from the cutting position adistance which includes the f distance for the lost motion, with aresultant disadvantage that the cutter is no longer capable ofcooperating with the feeding gear to hold the peripheral edge of anopened can therebetween. In fact, however, the spring not only retainsthe power transmission means but also is resiliently deformed a distancecorresponding to the distance of the lost motion to prevent the cutterblade overrunning so that the latter can cooperate with the feeding gearto grip the peripheral edge of an opened can therebetween to prevent thesame from falling down of the can opener. Therefore, the clearance forthe lost motion achieves its intended purpose.

The peripheral edge of a 'can is pinched between the feeding gear andthe cutter blade during and after the can opening operation of theblade. The barrel of the can is urged against one of the projections orend corners of the can bearing during the can opening operation. Whenthe can is opened, the can is rolled by gravity to and held in abutmentcontact with the other projection of the can bearing, said otherprojection extending laterally to an extent less than that of said oneprojection. This movement of the can produces an additional gap betweenthe cutter blade and the inner peripheral edge of the open top of thecan to reduce the friction between the cutter blade and the can. Thus,the returning force of a push-button switch itself will be sufficient toalso return the cutter blade to its original rest position. In order toprovide a conveniently opera ble can opener, therefore, a push-buttontype switch may be utilized without any improvement in the can opener ofthe present invention.

What is claimed is:

l. An electrically powered can opener comprising;

an electric motor;

a feeding gear mounted for rotation about a fixed axis and operativelyconnected to said motor to rotate and feed a can to be opened;

a cutter blade mounted for pivotal movement about the axis of asupporting shaft therefor, said blade being operable to cooperate withsaid feeding gear to pinch and hold such can so that said blade cuts thecover thereof;

a cam plate mounted for pivotal movement about the axis of a supportingshaft therefor, said cam plate being pivotally successively movable to afirst position in which the electrical circuit for said motor is closedwhen said cutter blade is positioned above said cover, to a secondposition in which said circuit is kept closed from the time said cutterblade is driven into said cover to the time said cutter blade completesits cutting operation, to a third position in which said circuit isopened to deenergize said motor when said cutter blade has completed itscutting operation and is cooperating with said feeding gear to hold saidcan, and to a fourth position in which said cam plate is prepared to bepivotally moved when said cutter blade has caused said can to bedisengaged from said cutter blade and said feeding gear;

means for pivotally moving said cam platelto said first, second andfourth positions and for stopping the pivotal movement of said cam plateat said third position;

esoY

means responsive to the pivotal movement of said cam plate for pivotallymoving said cutter blade; and

common means for actuating both of said cam plate moving means and saidcutter blade moving means.

2. An electrically powered can opener comprising;

an electric motor;

a feeding gear rotatably mounted on a base and operatively connected tosaid motor to rotate and feed a can to be opened;

a cutter blade rigidly secured to a mounting portion of an 'armpivotally movable about the axis of a supporting shaft onsaid base, saidmounting portion extending through an arcuate slot formed in said base,said cutter blade being operable to cooperate with said feeding gear topinch and hold such can so that said blade cuts the cover thereof;

a cam plate mounted for pivotal movement about the axis of a supportingshaft therefor, said cam plate being pivotally successively movable to afirst position in which the electrical circuit for said motor is closedwhen said cutter blade is positioned above said cover, to a secondposition in which said circuit is kept closed from the time said cutterblade is driven into said cover to the time said cutter blade completesits cutting operation, to a third position in which said circuit isopened to deenergize said motor when said cutter blade has completed itscutting operation and is cooperating with said feeding gear to hold saidcan, and to a fourth position in which said cam plate is prepared to bepivotally moved when said cutter blade has caused said can to bedisengaged from said cutter blade and said feeding gear;

a stop for stopping the pivotal movement of said cam plate at saidfourth position;

means responsive to the pivotal movement of said cam plate for pivotallymoving said cutter blade; and

common means for actuating both of said cam plate moving means and saidcutter blade moving means, said common means being biased in a directionopposite to the direction for said actuation.

3. An electrically powered can opener as claimed in claim l, in whichsaid cam plate includes a first inclined portion against which saidmeans for pivotally moving said cam plate is urged to move the same tosaid first position, a locking portion with which means for pivotallymoving said cam plate is engaged to hold the same in said thirdposition, a guide portion for positioning said cam plate in said secondposition and guiding said means for pivotally moving said cam plate tosaid locking portion after said cutter blade has cut the cover of a can,and a second inclined portion operable to unlock said means forpivotally moving said cam plate to position said cam plate in saidfourth position and to return the thus unlocked cam plate moving meansto a position in which said cam plate is prepared to be pivotally moved.

4. An electrically powered can opener as claimed in claim 3, in whichsaid cam plate is always actuated by a spring in a direction opposite tothe direction in which said cam plate is moved to close said electricalcircuit,

said cam plate being also slidably movable in the axial direction ofsaid supporting shaft on which said cam plate is pivotally mounted.

5. An electrically powered can opener as claimed in claim 3, in whichsaid cam plate is always actuated by a spring in a direction opposite tothe direction in which said cam plate is moved to close said electricalcircuit, said cam plate being also oscillatable in the axial directionof said supporting shaft on which said cam plate is pivotally mounted.

6. An electrically powered can opener as claimed in claim 3, in whichsaid cam plate is always actuated by a spring in a directionopposite tothe direction in which said cam plate is moved to close said electricalcircuit, said means for pivotally moving said cam plate being movablewith respect to said second inclined portion in a directionsubstantially prependicular to the plane in which said cam plate ispivotally movable.

7. An electrically powered can opener as claimed in claim l, in which aclearance is provided between said means for pivotally moving cutterblade and said cornmon means so that said means for pivotally movingsaid cam plate is movable a distance to unlock said cam plate in saidthird position and so that said cutter blade is not actuated to moveduring the movement of said cam plate moving means through saiddistance.

8. An electrically powered can opener as claimed in claim 7, in whichsaid clearance is formed by a hole in said common means and said meansfor pivotally moving'said cutter blade, the last-mentioned meanscomprising a pin member projecting from a pivotable arm and extendingloosely into said hole, said cutter blade being rigidly secured to saidpivotable arm.

9. An electrically poweredcan opener as claimed in claim 6, in whichsaid clearance is formed by a hole in said common means and means forpivotally moving said cutter blade, the last-mentioned means comprisinga pin member projecting from a pivotable arm and extending loosely intosaid hold, said cutter blade being rigidly secured to said pivotablearm, said pin member being biased by a spring means in a directionopposite to that in which said cutter blade is returned to its initialposition, said spring means being deformed when said means for pivotallymoving said cam plate is moved so as to be unlocked from said cam platewhich is positioned in said third position.

l0. An electrically powered can opener as claimed in claim l, in whichsaid cutter blade hasa generally triangular forward end to wedgesamevinto a cover of a can to be opened.

l1. An electrically powered can opener as claimed in claim l, in whichfirst and second projections are provided below and adjacent saidfeeding gear for bearing against the barrel of a can being opened, saidfirst bearing projection being adapted to bear against said barrel whilesaid cutter blade operates to cut the cover of said can, said can afterbeing opened being moved to an urged against said second bearingprojection so that the latter bears against said opened can, said secondprojection extending a distance less than that of said first projection.

1. An electrically powered can opener comprising; an electric motor; afeeding gear mounted for rotation about a fixed axis and operativelyconnected to said motor to rotate and feed a can to be opened; a cutterblade mounted for pivotal movement about the axis of a supporting shafttherefor, said blade being operable to cooperate with said feeding gearto pinch and hold such can so that said blade cuts the cover thereof; acam plate mounted for pivotal movement about the axis of a supportingshaft therefor, said cam plate being pivotally successively movable to afirst position in which the electrical circuit for said motor is closedwhen said cutter blade is positioned above said cover, to a secondposition in which said circuit is kept closed from the time said cutterblade is driven into said cover to the time said cutter blade completesits cutting operation, to a third position in which said circuit isopened to deenergize said motor when said cutter blade has completed itscutting operation and is cooperating with said feeding gear to hold saidcan, and to a fourth position in which said cam plate is prepared to bepivotally moved when said cutter blade has caused said can to bedisengaged from said cutter blade and said feeding gear; means forpivotally moving said cam plate to said first, second and fourthpositions and for stopping the pivotal movement of said cam plate atsaid third position; means responsive to the pivotal movement of saidcam plate for pivotally moving said cutter blade; and common means foractuating both of said cam plate moving means and said cutter blademoving means.
 2. An electrically powered can opener comprising; anelectric motor; a feeding gear rotatably mounted on a base andoperatively connected to said motor to rotate and feed a can to beopened; a cutter blade rigidly secured to a mounting portion of an armpivotally movable about the axis of a supporting shaft on said base,said mounting portion extending through an arcuate slot formed in saidbase, said cutter blade being operable to cooperate with said feedinggear to pinch and hold such can so that said blade cuts the coverthereof; a cam plate mounted for pivotal movement about the axis of asupporting shaft therefor, said cam plate being pivotally successivelymovable to a first position in which the electrical circuit for saidmotor is closed when said cutter blade is positioned above said cover,to a second position in which said circuit is kept closed from the timesaid cutter blade is driven into said cover to the time said cutterblade completes its cutting operation, to a third position in which saidcircuit is opened to deenergize said motor when said cutter blade hascompleted its cutting operation and is cooperating with said feedinggear to hold said can, and to a fourth position in which said cam plateis prepared to be pivotally moved when said cutter blade has caused saidcan to be disengaged from said cutter blade and said feeding gear; astop for stopping the pivotal movement of said cam plate at said fourthposition; means responsive to the pivotal movement of said cam plate forpivotally moving said cutter blade; and common means for actuating bothof said cam plate moving means and said cutter blade moving means, saidcommon means being biased in a direction opposite to the direction forsaid actuation.
 3. An electrically powered can opener as claimed inclaim 1, in which said cam plate includes a first inclined portionagainst which said means for pivotally moving said cam plate is urged tomove the same to said first position, a locking portion with which meansfor pivotally moving said cam plate is engaged to hold the same in saidthird position, a guide portion for positioning said cam plate in saidsecond position and guiding said means for pivotally moving said camplate to Said locking portion after said cutter blade has cut the coverof a can, and a second inclined portion operable to unlock said meansfor pivotally moving said cam plate to position said cam plate in saidfourth position and to return the thus unlocked cam plate moving meansto a position in which said cam plate is prepared to be pivotally moved.4. An electrically powered can opener as claimed in claim 3, in whichsaid cam plate is always actuated by a spring in a direction opposite tothe direction in which said cam plate is moved to close said electricalcircuit, said cam plate being also slidably movable in the axialdirection of said supporting shaft on which said cam plate is pivotallymounted.
 5. An electrically powered can opener as claimed in claim 3, inwhich said cam plate is always actuated by a spring in a directionopposite to the direction in which said cam plate is moved to close saidelectrical circuit, said cam plate being also oscillatable in the axialdirection of said supporting shaft on which said cam plate is pivotallymounted.
 6. An electrically powered can opener as claimed in claim 3, inwhich said cam plate is always actuated by a spring in a directionopposite to the direction in which said cam plate is moved to close saidelectrical circuit, said means for pivotally moving said cam plate beingmovable with respect to said second inclined portion in a directionsubstantially prependicular to the plane in which said cam plate ispivotally movable.
 7. An electrically powered can opener as claimed inclaim 1, in which a clearance is provided between said means forpivotally moving cutter blade and said common means so that said meansfor pivotally moving said cam plate is movable a distance to unlock saidcam plate in said third position and so that said cutter blade is notactuated to move during the movement of said cam plate moving meansthrough said distance.
 8. An electrically powered can opener as claimedin claim 7, in which said clearance is formed by a hole in said commonmeans and said means for pivotally moving said cutter blade, thelast-mentioned means comprising a pin member projecting from a pivotablearm and extending loosely into said hole, said cutter blade beingrigidly secured to said pivotable arm.
 9. An electrically powered canopener as claimed in claim 6, in which said clearance is formed by ahole in said common means and means for pivotally moving said cutterblade, the last-mentioned means comprising a pin member projecting froma pivotable arm and extending loosely into said hold, said cutter bladebeing rigidly secured to said pivotable arm, said pin member beingbiased by a spring means in a direction opposite to that in which saidcutter blade is returned to its initial position, said spring meansbeing deformed when said means for pivotally moving said cam plate ismoved so as to be unlocked from said cam plate which is positioned insaid third position.
 10. An electrically powered can opener as claimedin claim 1, in which said cutter blade has a generally triangularforward end to wedge same into a cover of a can to be opened.
 11. Anelectrically powered can opener as claimed in claim 1, in which firstand second projections are provided below and adjacent said feeding gearfor bearing against the barrel of a can being opened, said first bearingprojection being adapted to bear against said barrel while said cutterblade operates to cut the cover of said can, said can after being openedbeing moved to an urged against said second bearing projection so thatthe latter bears against said opened can, said second projectionextending a distance less than that of said first projection.